1. Field
The present invention relates generally to band pass RF filters and improvements thereof. More particularly, the invention relates to high power band pass RF filters with surge protection elements and improvements thereof.
2. Description of the Related Art
Band pass RF filters for use in electronic circuits or between systems or devices are known and used in the art. In-line RF filter devices are similarly known and used in the art. Often in electrical systems, it is desirable to control signal frequencies to a desired range of frequency values. Band pass filters can be used for such purposes by rejecting or attenuating frequencies outside the desired range. In-line band pass filter devices connected along a conductive path between a source and a connecting system will only pass the desired range of frequencies to the connecting system. Signal frequencies outside of the desired range would ideally be highly attenuated. A band pass filter should have as flat of a pass-band as possible so passed signals experience little to no attenuation. A band pass filter should also transition from the pass-band to outside the pass-band with a sharp roll-off, narrow in frequency, to limit the passing of partially attenuated signal frequencies existing outside the pass-band.
As systems and electronics increase in complexity and size, power requirements can increase as well. Even in simple systems or devices, large amounts of power may be required or transmitted along signal wires or transmission cables. Operating frequency requirements are often still present in such systems, illustrating the need for frequency filtering devices capable of operating at these increased power levels. Surge events, particularly in such high power applications, necessitate additional considerations since the filtering electronics may be subjected to significant over-voltage or over-current conditions. Thus, an ideal electronic filtering device for such applications would strongly attenuate out-of-band signals while performing little attenuation to in-band signals, operate in high power applications, manage surge conditions present at the device to prevent damage and have a low manufacturing cost.